Stretchable leather shoe



Dec. 19, 1939. A. vAMos 2,184,261

STRETCHABLE LEATHER SHOE Filed OC'b. 14, 1958 INVENTOR.

ATTORNEY Patented Dec. 19, 1939 'UNITED STATE-s PATENT OFFICEs'rRE'rcHABLE LEATHER suon Alfred Vamos, Brooklyn, N. Y., assignor, bymesne assignments, to United States Rubber Company, New- Jersey York,lN. Y., a corporation of New Application October 14, 1938, Serial No.234,862

3 Claims.

taneously returning to or nearly to' their original 5 dimensions or aredevoid of this property.

It has been proposed heretofore to secure a thin strip of leather to astrip of elastic webbing to form a leather covered elastic stripsuitablefor use as a belt-worn to support the trousers, but in `suchconstruction the wrinkles or lines formed transversely of the leather bythe contraction of the elastic webbing are not particularlyobjectionable.

. It has also been proposed heretofore to employ various types of.elastic webbing and gores in shoes to make them elastic, but thematerial which has been universally used for many years in making mosttypes of shoes is leather, and so far as I am aware, it is broadly newto form the upper portion of a shoe of leather that is adapted tostretch and contract with the foot movement,

`the same comprising a at sheet of shoe upper leather that has asubstantial stretch and to which is adhesively secured an elastic sheetadaptedto. hold the leather normally in the contracted condition.

The requirements of this stretchable plied material consisting ofstretchable leather having an elastic backing, in orderV to meet thedemands of 40 the shoe trade are exacting. One such requirement is thatths'material shall lie fiat and smooth and be capable of stretchingrepeatedly in the shoe throughout a substantial. range without causingany appreciable change in the appearance 45 of the leather. Anotherrequirement is that the leather be so firmly secured to the elasticbacking that .it will remain free from puckers and wrinkles throughoutthe life of .the shoe. Another requirement is that this leather materialbe indistinguishabe or practically indistinguishable in appearance fromthe non-stretchable leather forming the rest of the shoe upper. Afurther requirement is that this stretchable material be sufficientlydurable to retain its original stretch characteristic throughout thelife of the vshoe in which it is embodied. A still further requirementis that the elastic modulus of this combined leather and backing be suchthat it will stretch with the foot movement and contract with suicientforce to embrace the foot snugly and conformably without exertingsumcient pressure upon the foot to be painful even l when the shoe isworn continuouslyl for many hours.

In addition to the above it is highly desirable that this stretchableplied material be suiciently permeable to permit air to passtherethrough to thereby improve the foot Ventilating properties of theshoe. It is also desirable that this plied material be so constructedthat it Will -lay at and smooth in the plied sheet without tending tocurl up .or cause the leather to look different at its outer face fromordinary shoe upper leather.

This stretchable plied material may have the width of the entire skinfrom which the leather is secured and, the leather employed inthestretchable portion of a shoe maybe obtained from the same pig, kid,calf or other sknsused heretofore to form shoe upper leather. Carehowever should be taken to finish the leather for the present inventionso that it will retain or have imparted thereto much 'of the stretch ofthe original green skin. This may be accomplished by being careful notto stretch the skin duringv the tanning'and calendering operations andby imparting to the same a relatively soft pliable finish so that itwill have an easy and substantial stretch. To this end the skins may becalendered less or underlighter pressure than was customary heretoforein making shoe upper leather. This desired stretch may also be im-lparted to the finished shoe leather by the treatment described in theabove `mentioned application.

A primary feature of the present invention resides in a leather shoehaving the entire upper thereof or a substantial portion thereof formedof the above described stretchable elastic backed leatherso that theshoe will stretch and contract with the foot movement.

A shoe constructed as herein contemplated is much more comfortable tothe foot 'than the leather shoes available heretofore, and it ts thefoot better in that the present shoe is free to stretchand contract toconform to the particular shape of the foot of the wearer. Furthermorethe stretch-0f the `foot receiving opening of the present shoe makes itnow practical to construct shoes that have much higher uppers than theordinarypump without requiring the use of fastening means, since thestretch of the shoe will permit the insertion of the foot therein. Againthe stretch characteristic of the present shoe causes it to cling to thefoot much better than the ordinary leather shoe. This is particularlynoticeable in pumps for it is now possible to make a pump which fits thefoot with sufficient snugness to prevent it from' sliding up and down atthe heel without binding uncomfortably across the top of the foot.

Another feature of the present invention reu sides in a leather shoesuch as herein contemplated wherein the elastic and non-elastic portionsthereof are or may be undistinguishable in appearance, and still afurther feature resides in a shoe suchas herein contemplated wherein theelastic portions thereof affords the foot better ventilation than thenon-elastic portions, and also better ventilation than theordinaryleather shoes.

Still another feature of the present invention resides in the particulararrangement of this material in the shoe in respect to the clreetion ofstretch of this material therein.

In developing the shoe of the present invention it became necessary todepart radically from the long established practice of lasting leathershoes, for heretofore in lasting shoes the shoemaker-has been careful topull the shoe upper tightly over the last so as to remove all stretchand thereby prevent the shoe from stretching out of shape when in use.In constructing the shoe of the present invention special care must beexercised while lasting the same not to stretch the shoe more than aslight-amount so that it will have the desired elastic properties whenFig. 1, the leather of this plied sheet being partly rolled back.

Fig. 4 is a plan view showing the reverse side of the vamp and twoquarters cut from Fig. 3;

Fig; 5 is a vertical sectional view through the plied material showingthe fabric skived from the leather adjacent one edge thereof preparatoryto finishing the upper edge of this material;

Fig. 6 is a sectional view taken on the line 6 6 of Fig. 1 showing thestep of Fig. 5 carried forward to provide the upper edge of the shoewith a smooth nished edge; and

Fig. '7 isy a side elevation of a Womans shoe formed partly ofstretchable and partly of nonstretchable leather.

In carrying out the present invention, it is important to use shoe upperleather, that is leather which has the strength and durability of theshoe upper leather employedl heretofore but which has in additionthereto the desired amount of stretch. The softer glove leather stock isnot suiliciently tough and durable to give satisfactory service and wearin shoes when backed with an elastic sheet as herein contemplated.

When the stretchable and contractable plied material herein contemplatedis to be embodied in shoes it is important that its elastic modulus besufciently low to cause the pliedl material to stretch with the footmovement, otherwise the advantages herein contemplated in a shoe made ofsuch material would be lost. It has been found in practice that a shoeupper constructed of this plied material may be somewhat thinner thanthe ordinary shoe upper as constructed heretofore, since the backingmaterial adhesively secured to the inner face of the leather makes itunnecessary to use any other form of lining in the shoe.

In manufacturing this stretchable plied material for use in shoes thestretch employed may be from 10% to 50% depending upon the type of shoeand location of the plied material therein, and this stretch can besecured without causing the leather to wrinkle or pucker or otherwiseshow any appreciable change in its appearance throughout this range ofstretch. The stretch of this plied material desired in most shoes isabout 20% lto 25%, but as little as 10% stretch in the plied materialmay be sufficient when the entire upper portions of the shoe surroundingthe foot receiving opening is made of this material for' with such anarrangement a 10% stretch in the plied material will permit the throatof the shoe to stretch a quarter of an inch or more which may be allthat is desired.

When I rst became interested in the present invention I found itimpossible to secure from the tanners shoe upper leather having therequired amount of easy stretch, therefore I developed the treatmentdescribed in the above mentioned application to increase the range andease of stretch of the shoe upper leather as purchased from the tanner.More recently the tanners have made an eifort to supply my requirementsfor a stretchable shoe upper leather and I am now able to buy from themsuch a leather having a 25% or more easy stretch, this makingunnecessary in many cases the treatment described in the above mentionedapplication.

In carrying out the present invention, the stretchable leather asreceived from the tanner is first preferably skived to give it a uniformthickness, and it may be skived thinner than the leather commonly usedheretofore in shoe uppers because the elastic backing sheet reinforcesand strengthens the thin leather sheet. The skiving however should notbe carried to such an extent that it produces an excessively thinleather sheet that will not stand up or give good service in a shoe. Inmost cases this skived leather should not be less than 1454 of an inchthick.

When it is not necessary to skive the leather skin to reduce itsthickness, lit may be desirable to roughen that face of the skin towhich the adhesive is to be applied, with sandpaper or other rougheningmeans, in order that the adhesive may more firmly grip this surface ofthe leather. The adhesive binder may be applied to either the flesh sideor the grain side of the leather depending upon which face of theleather is to be exposed in the finished shoe but in either case theface should be roughened. When a suede leather is used having the fleshface finished and exposed at the outer face of the shoe the elasticbacking is applied to the previously roughened grain face.

After a leather skin has been acquired from the tanner having a desiredrange of stretch and sufficiently low elastic modulus, or has beentreated by the method described in the above application toY impart thedesired easy stretch thereto and has had the face to which the adhesiveis 'to be applied either skived or roughened, the adaisaaei o hesivebinder maybe applied. l

The adhesive' used is preferably a latex ade 'hesive which will give afirm bond without needing to be' vulcanized and the quickest and mostsatisfactory way yet devised for applying this latex-adhesive is by aspraying operation. One

important advantage obtained by spraying the latex upon the leather isthata good bond can be secured without decreasing the permeability ofthe. leather to air, This latex adhesive is preferably sprayed upon theleather skin while it rests upon a supporting surface in a fiat butunstretched condition.

After the stretchable skin has had the latex adhesiveapplied to one facethereof it may them be provided with theelastic backing.

Various elastic sheet materials which will maintain their elasticproperties throughout the life of the shoe may be used as a backing-forthe above described leather sheet to hold the `same normally in itscontracted condition, but

the-material preferably used is a sheet of lfine woven elastic fabricsuch as elastic batiste. 'The backing material preferably has a longerstretch than the leather so as not to interfere with the 1 stretch oftheleather and the contractive force may be as strong as needed for its usein the shoe. It isoimportant that this backing material be carefullyconstructed so that the tension and stretch characteristics of thefsameshall be uniform throughout that area which backs any one skin, becauseif local variation exists in the ten- 'sion ofthe backing fabric it willtend to pucker l or distort the skin to which it is secured.

This backing fabric should have a latex adhesivesprayed uponone facethereof similarly to the manner in which this adhesive is applied to theleather skin, and here again it is desirable that the latex be soapplied that it will not appreciably interfere with the passage of air'5 through the fabric. f

- in'an unstretched condition. yIt is found desirablewhile'unitingthesetwo. sheets or shortly thereafter to pass them between calenderrolls to increase the bond therebetween and force out any air whichmight be trapped. The stretchable plied material thus formed may then beplaced in a` at condition in a stack with other similarly formed sheetswhich, should be separated from each other`by sheets of cardboard placedbetween the backed leather sheets. They should be allowed to remain inthis stack for about 12 hours while the moisture of the latex adhesiveescapes or dries out. vThe materialis then ready to be embodied inshoes. l 'l It is found that the moisture of the latex binder has atendency to swell the textilebers forming the backing sheet. Therefore,'to reduce this `swelling tendency, it has been found desirable to treatthe face of the backing fabric to .which the latex is toy be appliedwitha light coating of any 'suitable water-repellant substance Vwhichwill lessen the tendency of the fibers l of this fabric to absorbmoisture fromthe adhesive. One well known water repellantV substancewhich vmay be used 'consists-of water containing about 2% emulsion ofsoap 'and carnauba wax.A

Most leather skins will stretch. more readily in the direction aroundthe animal fromwhich the portions thereof.

skin was taken than longitudinally of such animal, therefore the backingmaterial which is preferably a one-way stretch fabric is so ap'pliedl tothe skin that its direction of stretch will correspOnd with that of themaximum stretch of the skin. y

The treatment involved in imparting the desired amount ,of stretch tothe Vleather skin andl in adhesivelyl securing the elastic backingthereto need not in any way change the appearance of the 'outer face ofthe leather, and the total thickness of the two-ply material thus formedmay be less than %4'of an inch. The backed stretchable leather such asherein contemplated may have a stretch of 50% or more but a much lowerstretch is suicient in most shoes to impart the e bodying the materialtherein. It` will be understood, however, that this material may beemployed in various types of shoes and in various 'Referring to thedrawing the stretchable plied material Ill is formed of a sheet ofshoeupper' leathe; IIwhich has been treated bythe tanner or otherwise,l togive it a low elastic modular and the desired amount of stretch, and toone face of this sheet of leather is adhesively secured the elasticbacking sheet I2T A perforated rubber sheet may be employed as thebackinggsheet but it is preferable to use a fine woven elastic fabrichaving a fone-waystretch and having the elastic yarn I3 introducedtherein either as warp or weft. These elastic yarns are preferablyconstructed in accordance with the Adamson Patent No. 1,822,847 forelastic yarn. Such a woven elastic backing sheet makes an excellentlining for the portion of the shoe in which the stretchable leather isembodied and makes the use of any other lining in this area unnecessary.

The sheets II and I2 are secured together by an adhesive binder 'I4which is necessarily elastic to accommodate the stretch of the pliedmaterial and this adhesive binder is preferably-the latexv binder abovedescribed which is so applied to the leather and fabric that it will notappreciably l interfere with the passage of air through the stretchableplied material. By using a latex adhesive compound which is not toofluid and by employing a suciently small amount it is practrate thedirection in which the elastic yarns I3 extend in each. f e

The shoe illustrated in Figs. 1 and 2 differs from the ordinary oxfordin that the entire vamp area ofthe shoe is formed of the-stretchablevamp I5` which, is placed in the shoe so that the elastic yarns extendtransversely of the foot to -impart 'to this part of the shoe a stretchand contractive force'. crosswise of ythefoot as indicated by thearrowa.v The quarters I 6 and I1,

it`will b e noted, are so cut from the sheet I 0' that the elastic yarnsI3 extend in a diagonal direction. The arrangement is such that theportion of .each quarter lying in the vicinity of the throat stretchesin the direction indicated by the arrow b whereas the portion of thequarter lying at each side of the foot stretches diagonally of thematerial. The shoe of Figs. 1 and 2 may be built upon a lastas usual butit is desirable to s ecure a binding tape temporarily to certainportions of the inner face of the shoe material during the lastingoperation to prevent theupper from stretching too much at this time.

'The shoe may or may not have the usual box toe as there is noparticular point to having lthe extreme toe of the shoe stretchable. Thebox toe is omitted in the construction shown. The vamp I5 as shown issecured to the forward portion of the quarters lI6 and I'I by the usualseam I8 and these quarters are secured together at the rear of the shoealong the vertical seam I9. The shoe is shown as having the usual sole2|) and heel 2| and the forward ends of the quarters I6 and I'I may beprovided with the usual eyelets to receive the shoe lacing 22, and theshoe is provided with a tongue 23. The upper edge of the shoe around thefoot receiving opening may be variously finished to provide a smoothrounded stretchable edge and in the construction shown the finish issecured by skiving away the woven fabric I2 near the upper edge of theshoe 'so as to expose the inner face of the leather II as shown in Fig.5. 'Ihis exposed portion of the leather is then folded over upon theskived fabric I2 as shown in Fig. 6 and it may be secured in this foldedcondition by an adhesive and also by thezig-zag stitching 24 to therebyprovide a smooth rounded upper edge 25 around the foot receiving openingthat will stretch. y

The construction of the shoe illustrated in Figs.- l and 2 is such thatthe entire shoe upper is adapted to stretch and contract to accommodatethe foot movements and to conform snugly but comfortably to the contourof the foot. 'I'his is just the reverse to the ordinary leather shoe asconstructed heretofore wherein care is taken to prevent the shoe fromstretching when worn.

In the present shoe the entire forepart or vamp area is so constructedthat it will stretch transversely to relieve the pressure upon the toesand sensitive forepart of the foot whereas the upwardly convergingportions of the quarter in the vicinity of the throat of the shoe willexert a yielding but comfortable pressure about the foot to therebyyieldingly support the arch of the foot and prevent `the foot fromcrowding forward in the shoe, land the longitudinal stretch ofthe/quarters at the sides of the foot causes the shoe to t snugly at theh eeland around the foot receiving opening. Such a shoe is extremelystrong and durable and is capable of wearing as long and probably longerthan the ordinary nonelastic leather shoe and is far more comfortablethan the ordinary shoe, due to thefact that its stretch characteristicscause it to conform accurately to the contour of the foot and to yieldto the foot movement.

Referring now to the modified construction Shown in Fig. 7 wherein isillustrated a shoe in which the rear portion in the vicinity of thecounter has the usual non-elastic construction and the forepart isconstructed of the stretchable ply material I Il to therebyfimprove thefit of the shoe, and cause the same to stretch suflicently to permit theinsertion of the foot in the shoe and its removal therefrom withoutvrequiring the use of any form of fastening means even though the shoeillustrated is considerably higher in the throat area than the ordinarystep-in type of shoe. v

The shoe of Fig. 7 may have the usual sole 26 and heel 21 but the entireforepart at each side of the shoe is formed of the stretchable laminatedleather fabric l0. The heel embracing or counter portion 28, toe 29 anda narrow strip 30 extending upwardly along the throatrof `the shoe areformed of the usual non-stretchable leather. f The fabric I 0 ispreferably so placed in the shoe that the elastic yarns I3 extendapproximately'parallel to the longitudinal axis of the shoe. Thisconstruction permits the shoe to .stretch in the throat area from itsnormal posifitting shoe unless the shoe is custom made, due

to the fact that the ordinary' shoe is made upon a standard last andnearly every ones foot differs to some extent from the contour of thestandard last of the size shoe he wears. As a result of the presentinvention it is not necessary to have a shoe custom made to secure aperfect fit since the` stretch properties of the present shoe will causeit to mold or conform accurately to the foot ofthe wearer.

It is found that a shoe constructed as herein contemplated affords thefoot better ventilation than the ordinary leather shoe, since'in thepresent construction the permeability of the stretchable plied materialI0 is very nearly the same as the permeability of the leather sheet IIbefore the latex adhesive I4 is sprayed thereupon. This has beenestablished by experiments in which pieces of the leather II which hadnot had the latex applied thereto were fastened in a Having thusdescribed my invention what I' claim and desire to prot'ect byLettersPatent is:

1. A shoe of the type described having the It was found upper thereofformed in part of ordinary shoe upper leather and in part of an elasticplied inaterial at the instep, said plied material consisting of anouter sheet of durable leather having a smooth unwrinkled surface and asubstantial and easy stretch and being provided with an elastic backingsheet adhesively secured thereto and coextensive therewith so that bothsheets are free from stress in the relaxed plied material, and arrangedto provide the shoe with an elastic area of said material at the instepthat is capable of stretching and contracting with the longitudinal footmovement and of giving good wear in the shoe.

2. A shoe of the type described having the upper thereof formed with anelastic plied material in the area oi' the instep, said plied materialconsisting oi an outer sheet oi durable leather at least Vu of an inchthick having a smooth unwrinkled surface and a substantial and easystretchand being provided with an elastic backing sheet adhesivelysecured thereto and coextensive therewith so that both sheets are freefrom stress in the relaxed plied material, and' arranged to provide theshoe with an elastic area of said material at the instep that is capableof stretchingl land contracting with the longi-` upper leather and inpart of an. elastic plied material at the instep, the outer face of thetwo being matched so that they are practically indistinguishable inappearance, said plied material consisting of an outer sheet of durableleather having a smooth unwrinkled surface and a sub- 'stantial and easystretch and being provided with an elastic backing sheet adhesivelysecured thereto and coextensive therewith so that both sheets are freefrom stressy in the relaxed plied material, and arranged to providetheshoe with an elastic area 'of said material at the instep that iscapable of stretching and contracting with the longitudinal footmovement and of giving as good wear as said ordinary shoe 'upperleather.

ALFRED VAMOS.

